Looper-operating mechanism for sewing machines



LOOPER OPERATING MECHANISM FOR SEWING MACHINES Filed Jan. 28. 1926 3 Sheets-Sheet 1 i I\ 4 Q ii X 5 5' I l m 5 f t\ g E i I Q a I 0 M w NOV. 12, 1929. I BERGER 1,735,628

LOOPER OPERATINGMECHANISM FOR SEWING MACHINES Filed Jan. 28. 1926 5 Sheets-Sheet 3 it is downwardly, with Patented Nov. 12, 1929 I Users me JQSEPH BERGER, or UTIGA, new YORK, ASSTGNOR To Union srnomn MAcHInsCor/L- PANY, or CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS noornn-ornmirme iiEoHAivIst/I Foe sew-me Machines 'A ncat o'n'nea January as, 1926. Serial no. 84,402

The invention relates to new and useful improvements in looper operating mechanisms for sewing machines, and more par: ticularly to a mechanism which gives to the looper a variable movement.

An object of the invention is to provide a looper operating mechanism which is so constructed that the thread carrying looper is moved forward into'the loop of the needle thread more rapidly than it is retracted therefrom. V A

A further object of the invention is to provide a looper operating mechanism of the above type wherein the looper is positively moved by connected cranks'and links.

A still further object of the invention is to provide a ma.chinehaving' a needle which is moved upwardly much more rapidly than a thread carrying looper operating mechanism which is adapt ed to move the thread carrying loop'er more quickly into the thread carrying loop; than it is retracted therefrom. A

These and other obvious and will in p fully described.

In the drawings which show way of illustration one embodimentof the inven tion 1 art be hereinafter more Figure 1 is a view partly in side elevation and partly in section showing a machine embodying my improved looper operating mechanism;

Fig. 2 dle head of the machine mechanism connected to the nee'dle bar operating the same; V 1

Fig. 3 is a View partly in section and, part? ly in side elevation showing the essential arts of the v looper operating mechanism and the needlewith thelooper at thetorward end of its stroke, and 1 Fig. e is a view similar to Fig.18,-butshow+ ing the 'looper and the needle at the The invention isv isa' sectional view through the neeand showing the lowen end of its stroke directed broadly to a sewing machine havinga reciprocating needle bar carryinga needle, which needle bar is operated by devices constructed and are ranged so as'to move the needle bar more ob ects' will in part'be' "of the looper on 1 1 complishedwhile the c'rankon the shaft tor.

at the rear end of its stroke auxiliary housing 4 in which quickly on its upward stroke than on its downward stroke. This enables the needle to be quickly retracted from the goods :h'eing stitched and give ample time for the feeding'of the material. Associated with this variably timed operating mechanism for the needle is a variable looper moving mechanism. The looper is of the thread carrying type and moves into and out of the needle threadflloop and also laterally to avoid the needle as'is usual in this type o'fjm'achine,

The looper 1's moved into the needle thread loo-p very quickly and is retracted from the loop much more slowlyf This enables the looper to get into the needle-threadl'oop although the needle moves" to the upper eiid of its stroke very ql'lickly. The looper is moved by means of a crank in the main shaft to which a linkjis connected. This link in turn is eonnectedto a leverf The lever jiSiilil turn pivoted to a link" which is connected at its lowerend to a crank on the shaft which rigidly supports the loop ejr. pivoted at one side of a' line connecting the centers of the main shaft and the looper shaft,,an'd as a result, the links and leve'i. take such position movement is aceoni pli hed while the crank on th mains'haft is moving through an ar'c oi less than one hundred and eighty degrees, while the stroke ts. return movement I is acis movingthrough an are "of co siderably greater thanlone hundredand eighty; degrees, Referr ng more ndetail tothe drawings,

I The lever is rny improved invention is shownapplied to v a machine of thehtyp'e eis'e1 osed.in';detai1 in Serial No. 9,584, filed'Februafry 16 1925 p The machinej fconsists' of a: supporting the application of Christensen &'LeVesconte,

standard 1 which is provided'withan' over: v

hanging upper and 2 on which, a horiztmtal vided witha laterally projecting portionor a needlebar 5, is mountedv and reciprocates. 3 also carries a depending arm- 6. E tendQ- endin arm 6 is a work su' 'ort'i'n 'arm 7 o g a:

housingi'lism'ountedr ThishbusingB is pro- Thehousing 'ing laterallyfromthe lower endof fsaid de,.

' The' needle bar is reciprocated by means.

of a lever 12 which'is pivoted M13 in the auxiliary housing 4. This lever is connected by means of a link 14 to the needle bar 5.

' The lever 12 at its rear end isconnected to a link 15, and the link 15 is in turn connected to a crank 16 formed in a shaft 17. This shaft 17 is the main shaft of-the machine. The link 15 is'co-nnected at. 18 to I the lever 12, and this pivotal connection 18 feed of the'ma'chine.

and the, pivot of the lever 12 are so disposed relative to the shaft that the needle is moved to the loWer end of its stroke while the crank 16 is turning through an are considerably greater than one hundred and eighty degrees.

The needle barI-is raised'to the upper end through an arcof considerablyless thanjone hundredand eighty degrees. Thus it is that the needle is caused'to move quickly on its upstroke and. be withdrawn from the fabric at an early period in the'stitch cycle so as to permit the material to. be moved by the This needle operating of its stroke while this crank is passing mechanism per se forms no-part of the present conte above referred to.

40 by a presser' foot 19 carried by a presser bar invention, but is shown, described and claimed in the application of Christensen & Leves The material is held on the work support 20. It is fed off the'end ofthe worksupporting arm by a feed dog 21. carried by a feed bar 22. This feeding mechanism forms no part of the present invention and may be of the usual character; e V

The looper supporting shaft 8 is moved end wise' by means of a lever 23 whichis con nected by alink 24 to asleeve 25 mounted on i 26. The sleeve "is free 7 oscillations of the lever 23,

move the loopershaft endwise, I to the looper a needle avoidingmo-vement.

the looper shaft 7 between fixed collars '26,

on" the shaft so that the shaftmay .oscillate'in the sleeve; The however, will andthus give The lever 23' is oscillated by means ofian eccentric strap 27 which'cooperates with an eccentric 28 on the main shaft 17 Fixedv to the eccentric 283is1a crank pin 29. This crank pin is connected to a link 30. The link '30 is connected at 31'to an'elbowlever 32. The elbow lever 32 is securedto a short shaft 33 mounted in bearings'in' the frame of the machine; This shaft 33 merely per- *nrits; the lever to swing freely through the 1,735,e2s V movements of the link connected therewith. A link 34 is pivotally connected at 35 to the elbow lever 32. This pivotal connection 35 is located at the elbow in the lever. The link 34 is in turn connected to a crank 36 on the end of the looper supporting shaft 8.

When the parts are in the position shown in Fig. 3, the looper is at the forward end of its stroke, while when the parts are in the position shown in Fig." 4, the looper is at the rear end 'of-its stroke. The main shaft is turning in a counter clockwise direction as viewed in these figures of the drawings. It

wvill be apparent, therefore, that when the crank 29 moves from the broken line a2a" in Fig. 3, around to the broken line y3 of this figure, and. also Fig. 4, said crank will have moved through an arcv indicated by the line b which is considerably'greater than one hundred and eighty degrees. During this movement of the crank, the looper is retracted.

When the crank moves from the broken line 1 3 of Fig. 4, tothebroken line a2-w of this figure, it moves through an arc indicated by the line a, which is considerably less than one hundred and eighty degrees. During this movement of the crank, the looper receives its entire forward movement.

From the above it will be apparent that the looper has a very quick forward movement, and a relatively slow retractingmovement. These movements of the looper are timed to correspond to'the variable move ments .of the needle. In other words, dur ing a portion of the stitch cycle, which is considerably less than one-half of a stitch cycle the needlemoves from its lowest-to its extreme highest position, and the looper moves from its rear to its extreme forward.

position, and will, therefore,enter the needle thread loop with certainty. V This enables the needle to clearthe material at an early periodj in the stitch cycleland gives a much greater time for the feed to take place before the. needle again penetratesi'the material. I j

The machine .is designed particularly for rapid stitching oftubular articles such as sleeves, leg portions and the like, of garments,

and particularly to the stitching; of'these, tubular articles one after the other, the articles being'formed around a work supporting arm and stitched as they are fed off from V the arm. One article is stitched right after the other without stopping the machine, and

the machine is driven 'at'an exceedinglyhigh speed.- In order to render the machine efficient under these conditions, the variable op erating mechanism forthe needle and looper has been devised, This mechanisminsures proper stitch formation under the conditions statedf Y "It isj-ohviousthat minor changes in the details of construction and arrangement of the parts may be made Without departing izo from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Lettersshaft, a thread carry ng ing machines comprising a looper supporting looper rigidly secured to said shaft, an actuating shaft for said looper supporting shaft, a crank on said actuating shaft, a crank on said looper supporting shaft, a lever pivotally supported at one side of a line joining the centers of said shafts and having its pivotal axis substantially parallel with the axis of the actuating shaft, a link pivoted to the crank on the actuating shaft and to said lever, and a second link pivoted to the lever andto said crank on the looper shaft, said pivotalconnections between the'links and the lever being so disposed that the looper operating shaft is oscillated through its entire throw while the actuating shaft is moving through an arc of considerably less than one hundred and eighty degrees.

2. A looper operating mecha.-. ism for sewing machines comprising a looper supporting shaft, a thread carrying looper mounted thereon, said looper supporting shaft having a crank, an actuating shaft for the looper supporting shaft, a crank carried by said actuating shaft, an about a center at one side of a line joining the centers of said shafts, a link connecting the crank on the actuating shaft with the end of said elbow lever, a link connected to said lever at the elbow thereof and to the crank on the looper supporting shaft.

3. A looper operating mechanism for sewing machines comprising a looper supporting shaft, a thread carrying looper rigidly mounted thereon, said looper supporting shaft having a crank on the end thereof, an actuating shaft located above the looper supporting shaft and having a crank on the end thereof, an elbow lever pivoted at one side of a line joining the center of the shafts, a link connected to said crank on the end of the actuating shaft and to the end of a second bow thereof, and to the crank on the end of the looper supporting shaftr a. The combination of a reciprocating needle bar carrying a needle, a main actuate ing shaft having a. crank formed therein, a

lever connected to the needle bar and having a link connection with the-actuating shaft disposed so that said needle is moved from its lowest to its extreme upper position, while the main actuating shaft is rotating through an arc considerably less than one hundred and eighty degrees, a looper supporting shaft, a thread carrying loopercarried thereby and cooperating with said needle, devices operated by said main actuating shaft foroscillatin'g elbow lever pivoted to turn saidelbow lever, link connected to the lever at the elsaid looper supporting shaft, said devices including means whereby said looper is moved from the rear end of its stroke to the forward end of its stroke while the needle is moving on its up stroke.

5. The combination of a. reciprocating needle bar carrying a needle,-a main actuat ing shaft having a crank formed therein, a

lever connected to the needle bar and having a link connection with the actuating shaft. disposed so that said needle'is moved from its lowest to its extreme upper position, while the main actuating shaft-is rotating through i an arc considerably less than one hundred and I eighty degrees, a looper supporting shaft,.a thread carrying looper carried thereby and cooperating with said needle, said looper sup porting shaft having a crank, said main shaft having a crank, a lever pivotally supported at a point at one side of a line passing through the centers of said shafts, a link connecting the crank on the main actuating shaft with said lever, and a link connecting said lever with the crankon the looper supporting shaft, said links eing so disposed that said looper supporting shaft is oscillated so as to move said looper from therear end of its stroke to the forward end of its stroke while the needle is on its up stroke.

6. In a sewing machine, of a rotating shaft, a reciprocating needle, needle actuating devices connected with said shaft for imparting reciprocations to said needle, said devices being so disposed that less than half of a revolution of said shaft will he required to move the needle from one extreme position to the other andmorethan halfarevolution of said shaft will be required to move the needle on its return movement to the first named extreme position, a looper cooperating with said needle and devices for actuating said looper connected with said rotating shaft, said looper actuating device being so disposed and arranged as to cause the looper to reach its extreme positions at the same time as the needle. V

7. The combination of a reciprocating needle bar carrying a needle, means operate'dby said shaft for reciprocat ing said needle bar and moving the, needle bar more quickly on its upward stroke than on its downward stroke, a looper support, a looper rigidly secured tosaid support, means for moving said ward including links andleve'rs for connecting said looper support to said actuating shaft, said links and levers being constructed and arranged so as to move the looper throughout its entire forward stroke while the needle is on its upstroke, and forfmoving v JOSEPH BERGEB.

the combination an actuating shaft,

looper forward 7 and backiie 

